1. Field of the Invention
This invention relates in general to food processing machinery and more particularly to a machine for peeling, abrading, removing skin and surface blemishes, and the cleaning and polishing of various food products.
2. Description of the Related Art
It is well known that the peeling and cleaning of produce at a high rate with minimal waste and handling damage is important in the food handling industry. Attempts to accomplish this have presented difficulties due to many factors, including the highly irregular surfaces and size variations of certain produce such as potatoes. A significant difficulty is presented by the differences in density and the epidermis characteristics for different types of produce and different species of the same type of produce. These differences make it difficult to determine the optimum abrasive surface pressure for different types of produce to minimize bruising and other handling damage.
Various methods and devices have been developed in the past for this purpose with varying degrees of success. Other mechanical devices in the art often relied on gravitational tumbling of the produce in a peeling cage having an abrasive inner surface, with an auger being used to move the produce through the cage. Other devices use tubs having internal scraping surfaces such as carborundum and bristle spindles arranged in cascading frames or in a circular drum or trough structure. Most of these units have handling damage problems resulting from the tumbling action, auger-induced product movement, and the lack of contour action whereby the product has to be ground down to remove the deepest blemishes. Such shortcomings result in high produce losses and in excessive amounts of flushing water being used for removal of the waste. Environmental considerations associated with the difficulties in disposing of the flush water and waste, along with the other shortcomings, resulted in the development of various means for utilizing steam, chemicals, infrared rays, lasers and the like. Many of these attempts provided results that were less than desirable.
For example, when high pressure steam was used it only partially boiled off the skin and the produce, potatoes for example, had to be subsequently processed in a skin eliminator, which resulted in the use of large quantities of water.
Attempts have been made to overcome the excessive use of flush water, and various inventions are concerned with such attempts. These inventions include spindle drums, perforated drums or cages which are defined by spaced apart rods, or carborundum units. Moreover, attempts to save water have also consisted of simply not using water. However, such attempts result in machinery that becomes cloyed with waste products (e.g., starch) and inoperable in short order.
Applicant""s U.S. Pat. No. Re.35,789 overcame many of the shortcomings of the related art. The disclosed structure includes inner and outer inverted frusto-conical cones which are arranged in a concentrically spaced relationship to provide a vertically diverging product cleaning space therebetween. The cones are rotatably driven so that centrifugal force applies horizontal and vertical components of force on the product being processed. The product is introduced into the center of the inner cone, moves horizontally through the product receiving vestibule at the bottom of the cones, and then moves angularly and upwardly through the product cleaning space. Centrifugal force holds the product in contact with the inner surface of the outer cone while abrading elements in the form of whips provided on the exterior surface of the inner cone accomplish the peeling, abrading, cleaning and polishing operations. The waste materials such as dirt and peelings are expelled under the influence of centrifugal force through apertures provided in the side wall of the outer cone. This disclosed structure does away with the need to use waste flushing water by using centrifugal force to accomplish the removal of waste materials. Also, the whips accomplish effective contour action to process the product with minimal handling damage. However in some instances, movement of the product through the structure has been less than ideal. For example, the product will sometimes bunch up in the transition area between the horizontal vestibule and the diverging product cleaning space.
Therefore, a need exists for a new and useful produce processing machine which overcomes some of the problems and shortcomings of the related art.
The invention relates in general to a novel food processing machine that includes two concentrically disposed drums that rotate about a horizontal axis. More particularly, the present invention discloses a machine having a cylindrical product cleaning drum mounted on a central shaft that is rotatably driven by a suitable drive means. A cylindrical product carrier shell is concentrically disposed relative to the cleaning drum and is spaced therefrom to provide an annular product cleaning space therebetween. A waste collecting bell of frusto-conical configuration is mounted in a concentrically spaced position about the carrier shell to provide a waste collecting space between the periphery of the carrier shell and the interior of the collecting bell. The carrier shell and the collecting bell are interconnected and are supported for rotation as a unit on trundle bearings with the rotational driving being provided by a second drive means. The products to be processed are fed into a feed chute from a suitable conveyer and deposited in a vestibule area at the input end of the machine. A transition area is provided between the vestibule area and the cleaning space with the transition area being defined by a frusto-conical nose cone on the front end of the cleaning drum and a similarly configured nose cone on the front end of the product carrier shell. Products introduced into the vestibule area will move into and through the diverging transition area into the annular cleaning space under the influence of centrifugal force produced by rotational driving of the cleaning drum and the interconnected carrier shell and waste collecting bell.
Preferably, the exterior peripheral surface of the cleaning drum nose cone is provided with abrading members in the form of whips, or bristles, with those disposed at the small end of the cone being relatively short and soft and those disposed between the small end and the larger end progressively increasing in length and stiffness. The products entering the transition area will be accelerated under the influence of centrifugal force and the diverging configuration of the area and will be gradually introduced to the abrading forces applied by the whips. Moreover, the abrading forces applied to the products in the transition area will rotate them and dislodge dirt and other foreign objects, which exit the area through suitable openings provided in the carrier shell""s nose cone.
A plurality of abrading members in the form of bristles, or whips, are mounted in a manner to hereinafter be described, so as to substantially cover the peripheral surface of the cleaning drum. The whips are for abrading the surface of the products as they move through the cleaning space between the cleaning drum and the carrier shell. The surface pressure applied on the products is adjustably controlled by changing the rotational speed of the cleaning drum so that the machine can be used to either clean and polish the products without disturbing the skin or to peel and remove surface-imperfections. This adjustable capability is also effected by altering the differential rotational speeds of the cleaning drum and the interconnected carrier shell and collector bell and by driving them in counter rotating or co-rotating directions. The surface pressure can also be altered by employing adjustable ex-center devices to mount the cleaning drum on the drive shaft. The ex-center mounting devices are used to mount the cleaning drum with an adjustable eccentricity so the drum wobbles when it is rotatably driven.
The abrading whips are carried on a plurality of arcuate segments, preferably four or six in number, that are mounted so as to extend from the peripheral surface of the cleaning drum and are radially movable relative thereto. The radial movement of the segments is controlled automatically in a preferred embodiment by compression springs which bias the segments inwardly toward the cleaning drum and allow them to move radially outwardly under the influence of centrifugal force. Such radial movement is used to compensate for wear on the whips and to augment the application of surface pressure on the products by increasing the rotational speed of the cleaning drum and thereby increasing the radial extension of the segments. In another embodiment, the radial movement of the segments is mechanically adjusted to alter the radial extension of the arcuate segments from the periphery of the cleaning drum.
The carrier shell is provided with a plurality of openings, each having a diameter in the range of from one half (xc2xd) to two and one half (2xc2xd) inches and preferably two (2) inches. The openings are arranged in a closely spaced array so as to cover the entire cylindrical surface of the carrier shell and pass through the wall thereof. Preferably, a layer of soft deformable material, such as gum rubber, is affixed to the inner surface of the cylindrical wall so as to line the inner surface and underlay each of the openings provided in the shell""s cylindrical wall. Centrifugal force exerted on the products moving through the cleaning space will press them into engagement with the deformable layer and the products will xe2x80x9cnestxe2x80x9d in the areas where the deformable material underlays the openings in the carrier shell wall. Such xe2x80x9cnestingxe2x80x9d of the products, along with the inherent frictional griping of the deformable layer, allows the whips to randomly rotate the products to thoroughly treat their surfaces. The deformable liner is provided with a plurality of relatively small openings in each of the areas thereof which underlie the larger openings provided in the wall of the carrier shell. Waste materials from the products being treated will be moved by centrifugal force through the holes in the deformable liner and will enter into the waste collecting space provided between the carrier shell and the collector bell. The waste materials will impinge on the inner surface of the waste collector bell and centrifugal force acting on the waste material will move it along the surface which diverges toward the product discharge end of the machine. Dust resulting from the product cleaning process is collected in a cowling which in a first embodiment encircles the outlet end of the collector bell and a tube is provided for connection to a source of negative pressure to provide a partial vacuum inside the cowling. Heavier waste materials that are held in engagement with the inner surface of the collector bell will slide off of the outlet end of the inner surface and in some cases will need to be scraped off, and, in either case, they are removed by suitable transporting and disposal equipment. In a second embodiment, the collector bell is formed of two pieces which are interconnected and configured to provide an annular opening in the wall of the collector bell. A dust collecting cowling circumscribes the collector bell in the area of the annular opening and a suitable source of negative pressure is coupled to the cowling.
The products being processed are pushed through the cleaning space between the cleaning drum and the carrier shell by the incoming products which are accelerated as they move into and through the transition area. When the products being processed reach the product discharge end of the cleaning drum they move onto an idler wheel which eases them down through a product collecting cowling and out through a discharge chute.
Residence time, that is the time that the products are in the cleaning space between the cleaning drum and the carrier shell, can be varied to suit the particular type of products being processed. The machine is supported on adjustable legs so that the machine can be tilted to change the angle of the rotational axis of the rotatably driven components relative to the horizontal.